Is Drowner Initiate legal in Standard, Modern, and Commander?

Drowner Initiate is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Drowner Initiate?

Drowner Initiate is a Creature — Merfolk Wizard. Its oracle text reads: "Whenever a player casts a blue spell, you may pay {1}. If you do, target player mills two cards. *Nothing satisfies a merrow as much as drowning what it cannot have.* Power/Toughness: 1/1"